1. Field of the Invention
The present invention relates to a slot machine.
2. Description of the Related Art
Conventionally, slot machines known as a type of gaming machines are constituted so as to: start games by players inserting coins or the like into the gaming machine; variably display columns of symbols in predetermined regions of the gaming machine while they are displayed in a stopped state after a predetermined period has elapsed; and award payout based on a combination of symbols in a stopped state.
In addition, the above slot machines are generally constituted to judge whether or not a winning combination allowed to award payout is established, based on whether or not a predetermined number of symbols of the same type (for example, “CHERRY” or “7”) are arranged along a preset payline. In the conventional slot machine, in a case where a predetermined number or more of symbols of the same type are arranged, it has been a common routine to award payout based on the number of the aforementioned arranged symbols, regardless of the payout line.
Further, many of the conventional slot machines have been known which conduct two types of games, i.e., a basic game and a free game. The basic game is executed upon consumption of gaming values (such as coins or credits) corresponding to the amount of bet. On the other hand, the free game is executed without consuming gaming values corresponding to the amount of bet.
The basic game is switched to the free game when a predetermined condition is met. The condition includes a case in which, for example, a specific symbol is displayed in a stopped state during the basic game. The free game is switched to the basic game when a predetermined condition is met. The condition includes a case in which, for example, the free games are executed a predetermined number of times.
In the conventional slot machines, it has been a common routine to raise players' feeling of expectation for the free game by changing arrangement of symbols during the free game differently from that during the basic game. For example, U.S. Pat. No. 6,394,902-B1 describes a slot machine in which a total of fifteen symbols are displayed in three rows and five columns with the use of video reels. This slot machine changes symbol columns arranged on reels during the free game differently from that during the basic game, in which eight types of symbols are decreased to five. In this manner, a probability of awarding payout can be apparently increased during the free game.
In the aforementioned conventional slot machines, however, irrespective of whichever of the basic game and the free game is in progress, the symbols of different types have been randomly arranged in combination and sequential order. These slot machines determine the contents of the prize to be awarded, based on a combination of multiple symbols that have been arranged in a display device. Therefore, players are allowed to have the feeling of expectation only for random payout based on a combination of plural types of symbols that have been randomly arranged in the display device. Accordingly, a need exists for the advent of a slot machine which can offer new entertainability.
The present invention has been made in view of the above-described circumstance. It is an object of the present invention to provide a novel slot machine by enhancing entertainability associated with arrangement of the symbols during the free game.